Device for cultivating soil or brushing debris having a drive shaft and plurality of gears

ABSTRACT

A device for cultivating soil or brushing debris includes a frame supporting a transmission and a motor. The transmission defines a housing. A drive shaft, which is at least partially surrounded by the housing, is driven by the motor. The drive shaft is a worm having a first set of threads on an exterior surface thereof and a second set of threads on the exterior surface thereof. The first set of threads are spaced-apart from and angled with respect to the second set of threads. A first gear, a second gear, and a third gear are all supported at least partially within the housing. External teeth of the second gear are in constant engagement with external teeth of both the first and third gears. A shaft is fixedly attached to the second gear and an assembly is removable attached to the shaft.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 13/033,720, filed Feb. 24, 2011 and entitled “Device for CultivatingSoil or Brushing Debris,” which claims the benefit of U.S. ProvisionalPatent Application No. 61/308,475, filed Feb. 26, 2010 and entitled“Convertible Tiller with Split Tines,” the entire subject matter ofwhich is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention is directed generally to a device for cultivatingsoil or brushing debris and, more particularly, to a tiller, cultivatoror brushing apparatus that is selectively reconfigurable to include, forexample, additional or fewer tines, a larger or smaller tine shield, ora brush attachment, and to a tiller, cultivator or brushing apparatusthat is selectively reversible.

Manually operated tillers or cultivators, which are generallymanufactured in three sizes, including large, mid-size and small or“mini,” are well known. Large tillers, which are the walk-behind-typeand/or motor driven, are heavy and bulky. As a result, large tillers canbe difficult to maneuver or transport and store. Mid-size tillers arealso walk-behind-units that are self-propelled, have large horse power(Hp) engines, are relatively heavy and are not meant for a single personto lift into or transport in a car, for example. Due to their size andweight, mid-size tillers are used for relatively large-scale tilling,such as in gardens, flower beds or in other locations where large areasneed cultivating. While walk-behind-type tillers, such as the large andmid-size models, have been available with drive controls ortransmissions that permit selective disengagement of power to the tines,such drive controls are complicated and require levers for changingoperation.

Mini tillers are compact, generally less than ten inches wide,light-weight (often around twenty-two pounds) and capable of beingeasily transported in a car, for example. Mini tillers are easier tomaneuver due to their light-weight and relatively small width, and arealso easier to store. With a mini tiller, the operating controls aresimple and easy to use and understand. Mini tillers generally include anengine, such as a 2-cycle gas, 4-cycle gas or electric motor, tines thatdig into the ground to penetrate and pulverize the soil; and a geartrain housing assembly, sometimes called the “transmission,” which has ahousing enclosing gears that drive a tine shaft attached to the tines.Typically, mini tillers include a handle to allow a user to guide ormaneuver the unit. A shield may cover the tines and prevent debris frombeing thrown toward the user, for example.

Typically, large and mid-size operated tillers are driven in the samedirection as the rotary movement of the tines, such that the tinerotation tends to assist in moving the unit forward. However, the normaloperation of a mini tiller is by pulling against the rotation of thetines. That is, the tines rotate in a forward direction, but properoperation of the tiller includes pulling the tiller back toward theoperator, in the direction opposite in which the tiller would tend totravel due to the rotation of the tines. Thus, for small tillers, themethod of tilling is by pulling the unit in the opposite direction ofthe tine rotation, such that while the tines are moving forward and awayfrom the operator, the tiller is pulled toward the operator.

There are several desirable structural and operational features thatconventional mini-tillers lack. For example, conventional mini-tillersdo not allow a user to selectively change the width of the tiller.Further, conventional mini-tillers do not offer the user the ability toperform larger tilling tasks and then covert the tiller to a smallersize to perform smaller tilling tasks, or vice-versa. Instead, the usermust purchase multiple tillers of varying size or width to accomplishtilling tasks of varying size. The ability to till or cultivate theground using a mini tiller on a relatively large area would takeconsiderable time. However, if an individual buys a large tiller, itcannot be used to go between the rows of plants for weeding, forexample, and it would be difficult to transport the large tiller toother locations. Currently, the individual would have to purchase both alarge tiller and a small tiller to complete both jobs. Thus, in today'stiller market, there is a gap with no one product to accomplish the jobof both mini and larger tillers.

Further, the ability to reverse or change the rotational direction ofthe tines is not currently possible on mini tillers. Conventionalreversing mechanism are not able to be supported or included inconventional mini tillers due to their large size, complex mechanisms,and relatively high weight. Thus, it is currently difficult to changethe direction of rotation of the tines on mini tillers due to the limitsof size, weight, costs, and requirements for space on mini tillers. Theability to change the rotational direction of the tines is advantageousto allow a user to back-up the tiller in the event that an object isinadvertently run over or to add a particular attachment to the tiller.To effectuate the reverse feature on large and mid-size tillers, theoperator is required to stop the tiller, reach down and move a lever. Ineffect, the operator is inserting/replacing one gear or gear group foranother in the gear train, which, in turn, reverses the direction of therotating gear and results in reversal of the rotational direction of thetine(s).

Those skilled in the art can appreciate the complicated mechanicalrequirements of redirecting the rotation through a different gear trainby insertion. For example, slippage of the gears can occur if they arenot properly engaged or aligned. Further, if the engagement is not doneproperly and the operator starts the tiller, grinding of the gear teethcan occur. Other times, the operator may start to use the tiller in thereverse direction only to have the lever “pop” back into the otherdirection (i.e., forward). Also, dirt or other foreign objects may fallinto a slot that surrounds the lever, which can cause the gears todisengage, for example. Thus, improper operation of the tiller may bethe result of any one of a number of reasons.

Therefore, there exists a need for a state-of-the-art compact tiller orcultivator that accurately controls engine speed, reduces noise, canselectively be increased or reduced in size, adds little weight, doesnot increase drag, and is easy to assemble. There exists a need for asmaller size tiller, cultivator or brushing apparatus to be able toconvert to a larger size tiller, cultivator or brushing apparatus forlarger projects. There is a need for a new innovative design that can beused in limited or confined spaces and fills the market gap between themid-size and mini tiller. Further, it would be desirable to provide anaccurate method of reversing a gear train of a tiller, cultivator orbrushing apparatus without having to open holes, slots, or gaps within aportion of the tiller, cultivator or brushing apparatus. Thus, thereexists a need for the user to be able to operate, adjust from forward toreverse, set and lock functions, and see results without leaving theoperating position. The present invention fulfills the above-identifiedneeds.

BRIEF SUMMARY OF THE INVENTION

Briefly stated, one aspect of a preferred embodiment of the presentinvention is directed to a device for cultivating soil or brushingdebris including a frame supporting a transmission and a motor. Thetransmission defines a housing. A drive-shaft, which is at leastpartially surrounded by the housing, is driven by the motor. The driveshaft is a worm having a first set of threads on an exterior surfacethereof and a second set of threads on the exterior surface thereof. Thefirst set of threads are spaced-apart from and angled with respect tothe second set of threads. A first gear, a second gear, and a third gearare all supported at least partially within the housing. External teethof the second gear are in constant engagement with external teeth ofboth the first and third gears. A shaft is fixedly attached to thesecond gear and an assembly is removable attached to the shaft.

In another aspect, a preferred embodiment of the present invention isdirected to a device for cultivating soil or brushing debris including aframe supporting a transmission and a motor. The transmission defines ahousing. A shaft is rotatably supported by the housing and is driven bythe motor through the transmission. A distal end of the shaft isspaced-apart from the housing and has a passageway therethrough. Atleast one fastener is sized and shaped to be at least partially receivedwithin the passageway of the shaft. One of a tine assembly and a tube isremovable attached to the shaft. The tine assembly includes a first pairof two laterally spaced-apart tine disks. Each tine disk includes atleast one blade for directly engaging and cultivating soil. The firstpair of tine disks being laterally positioned on the shaft between thefastener and the housing. The tube includes a wheel rotatably attachedto a first end thereof and a first gear fixedly attached to an opposingsecond end thereof. At least a portion of the at least one fastenerextends through at least a portion of the tube to fixedly attach thetube to the shaft.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended drawings. For the purpose of illustrating the invention,there are shown in the drawings embodiments which are presentlypreferred. It should be understood, however, that the invention is notlimited to the precise arrangements and instrumentalities shown. In thedrawings:

FIG. 1 is a front right-side perspective view of a tiller or cultivatorin a partially disassembled configuration in accordance with a firstpreferred embodiment of the present invention;

FIG. 1A is an enlarged front left-side perspective view of a baseportion of the tiller or cultivator shown in FIG. 1 in a fully assembledconfiguration;

FIG. 2 is a front left-side perspective view of a base portion of atiller or cultivator in accordance with a second preferred embodiment ofthe present invention, with a shield shown in a retracted configuration;

FIG. 3 is a front left-side perspective view of a base portion of atiller or cultivator in accordance with a third preferred embodiment ofthe present invention, with a shield shown in a retracted configurationand tine extensions removed from the tiller or cultivator;

FIG. 3A is a front left-side perspective view of the base portion of thetiller or cultivator shown in FIG. 3, with the tine shield shown in anexpanded configuration;

FIG. 3B is a front elevation view of the base portion of the tiller orcultivator shown in FIG. 3A;

FIG. 3C is a partially exploded perspective view of the base portion ofthe tiller or cultivator shown in FIGS. 3A and 3B;

FIG. 4 is a greatly enlarged perspective view of one end of a shaft ofthe base portion of the tiller or cultivator shown in FIGS. 1-3C;

FIG. 5 is a greatly enlarged top perspective view of a center portion ofthe shield shown in FIGS. 3-3C;

FIG. 6 is a top perspective view of a left extension of the shield shownin FIGS. 3-3C;

FIG. 6A is a top perspective view of a right extension of the shieldshown in FIGS. 3-3C;

FIG. 7 is a front elevational view of a shield in accordance with afourth preferred embodiment of the present invention;

FIG. 8 is a top perspective view of a tool for inserting or removing afastener into or from the base portion of a tiller or cultivator inaccordance with a preferred embodiment of the present invention;

FIG. 8A is a left-side elevation view of the tool and fastener shown inFIG. 8, wherein the tool is being used to insert the fastener into thefirst end of the shaft of the tiller or cultivator;

FIG. 9 is a top perspective exploded view of a partially disassembledportion of a tiller or cultivator in accordance with a preferredembodiment of the present invention;

FIG. 9A is a front elevation exploded view of the partially disassembledportion of the tiller or cultivator shown in FIG. 9;

FIG. 9B is an enlarged top perspective view of a connector piece shownin FIGS. 9 and 9A;

FIG. 9C is a side elevation view of the connector piece shown in FIG.9B;

FIG. 9D is a rear perspective exploded view of a partially disassembledportion of a tiller or cultivator in accordance with an alternativepreferred embodiment of the present invention;

FIG. 10 is a front perspective exploded view of a partially disassembledportion of a tiller or cultivator in accordance with another preferredembodiment of the present invention;

FIG. 10A is a front elevation exploded view of the partiallydisassembled portion of the tiller or cultivator shown in FIG. 10;

FIG. 11 is a front perspective exploded view of a partially disassembledportion of a tiller or cultivator in accordance with another preferredembodiment of the present invention;

FIG. 11A is a front elevation exploded view of the partiallydisassembled portion of the tiller or cultivator shown in FIG. 11;

FIG. 11B is a greatly enlarged top perspective view of a connector pieceshown in FIGS. 11 and 11A;

FIG. 11C is a side elevation view of the connector piece shown in FIG.11B;

FIG. 12 is a front perspective exploded view of a partially disassembledportion of a tiller or cultivator in accordance with a another preferredembodiment of the present invention;

FIG. 12A is a front elevation exploded view of the partiallydisassembled portion of the tiller or cultivator shown in FIG. 12;

FIG. 13 is a rear perspective exploded view of a partially disassembledportion of a tiller or cultivator in accordance with another preferredembodiment of the present invention;

FIG. 13A is an enlarged rear perspective view of the partiallydisassembled portion of the tiller or cultivator shown in FIG. 13;

FIG. 14 is a front perspective view of a partially disassembled portionof a tiller or cultivator in accordance with another preferredembodiment of the present invention;

FIG. 15 is a rear perspective view of a preferred embodiment of a clutchdrum assembly shown in an installed configuration on the transmissionhousing of the tiller or cultivator shown in FIG. 3A;

FIG. 15A is an enlarged exploded top perspective view of the clutch drumassembly shown in FIG. 15;

FIG. 16 is a perspective view of a cross member in accordance with apreferred embodiment of the present invention, wherein the tool of FIGS.8 and 8A is shown attached to the cross member;

FIG. 17 is an top perspective view of brush attachment in accordancewith a preferred embodiment of the present invention, wherein the brushattachment is shown in place of tines on the base portion of the tilleror cultivator of FIG. 1;

FIG. 17A is a top plan view of the brush attachment shown in FIG. 17 andthe base portion of the tiller or cultivator;

FIG. 17B is a top perspective view of the brush attachment shown inFIGS. 17 and 17A and the base portion of the tiller or cultivator, witha portion removed for clarity;

FIG. 18 is a schematic side elevation view of a reverse mechanism inaccordance with a preferred embodiment of the present invention, withthe reverse mechanism in a first or forward configuration;

FIG. 18A is a schematic side elevation view of the reverse mechanismshown in FIG. 18, with the reverse mechanism in a second or neutralconfiguration; and

FIG. 18B is a schematic side elevation view of the reverse mechanismshown in FIG. 18, with the reverse mechanism in a third or reverseconfiguration.

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used in the following description for convenienceonly and is not limiting. The word “upper” designates a direction in thedrawings to which reference is made. The words “inner” and “outer” referto directions toward and away from, respectively, the geometric centerof the device, and designated parts thereof, in accordance with thepresent invention. The words “right,” “left,” “front” and “rear” referto directions in the drawings from the perspective of an individual oruser holding handle bars of the device and facing toward the device(i.e., opposite from the perspective when viewing the figures). Unlessspecifically set forth herein, the terms “a,” “an” and “the” are notlimited to one element, but instead should be read as meaning “at leastone.” The terminology includes the above-listed words, derivativesthereof and words of similar import.

Referring to the drawings in detail, wherein like numerals indicate likeelements throughout the several views, FIGS. 1-18B show a tiller,cultivator or brushing apparatus, generally designated 10 (referred tosimply as “tiller”), and various parts, components, tools or attachmentsthereof in accordance with several preferred embodiments of the presentinvention. The tiller 10 is preferably capable of cultivating orturning-over soil, for example, or brushing or sweeping debris in atleast two distinct configurations or sizes. The tiller 10 is alsopreferably capable of selectively accommodating or attaching to one ormore tine assemblies 12 a, 12 b and one or more of a variety ofattachments, such as a brush (FIG. 17) for dispersing snow, a broom, apaddle, or clippers. Although reference is made hereinafter to a “tiller10,” the present invention is not so limited. Specifically, thestructural or operational features described herein may also beincorporated or employed in a cultivator, an edger, a bed redefiner, aplanter or furrower, a plow, a lawn dethatcher, an aerator, a cleaner orsweeper, a hedge trimmer, or any other garden, lawn or hardtopmaintenance apparatus, either commercial or personal/residential, forexample.

Referring specifically to FIG. 1, the tiller 10 preferably includes aframe supporting a transmission or gear train assembly 13, described indetail below, operatively connected to a power unit 14, such as anelectric or gas engine or motor. If electric, the power unit 14 may bean alternating current (AC) or direct current (DC) motor. A printedcircuit board (PCB) (not shown) may be placed in, on or proximate to thepower unit 14 to provide speed control thereto. In an embodimentemploying an electric motor, an AC supply or a battery (not shown)preferably supplies the power or energy to the motor. In an embodimentin which the power supply is AC and the motor is DC, the PCB wouldpreferably be capable of converting the AC to DC. Alternatively, if thepower supply is DC from a battery and the motor is DC, the PCB wouldpreferably control the speed by regulating voltage and current to the DCmotor. Further, if the motor voltage and the battery voltage were notthe same, the PCB would preferably step up (i.e., increase) or step down(i.e., decrease) the voltage in order to supply the proper voltage tothe motor. In an embodiment employing a gas or diesel engine, a numberof different power options are available. For a gas engine, themanufacturer can select a four stroke (cycle) or a two stroke (cycle)engine, for example.

As seen in FIGS. 1, 3C, 4, 8, 8A, 9, 9A, 9D, 11A, 12-13 and 14, a shaftor tine shaft 15 preferably extends outwardly from opposing side wallsof a housing 16 defined by the transmission 13. The tine shaft 15 is atleast partially surrounded by the housing 16 and is preferably rotatablysupported by one or more bearings (not shown) of the transmission 13,such that the tine shaft 15 is rotatable with respect to thetransmission 13 and/or housing 16. As understood by those skilled in theart, the transmission 13 operatively connects the tine shaft 15 to thepower unit 14, such that operation of the power unit 14 rotates the tineshaft 15. As shown in FIG. 3B, a longitudinal axis 16 a of the housing16 of the transmission 13 preferably extends generally, if not exactly,perpendicular to a longitudinal axis 15 c of the tine shaft 15. Further,the longitudinal axis 15 c of the tine shaft 15 preferably extendsgenerally, if not exactly, parallel to a ground surface (not shown)during proper operation of the tiller 10. The tine shaft 15 may be asingle, unitary shaft that extends through the housing 16, or the tineshaft 15 may be two separate or independent shafts that extend outwardlyfrom the housing 16 of the transmission 13 in opposing directions (i.e.,180 degrees from each other). While reference is made herein after tothe tine shaft 15, such description is not limiting to a single, unitaryshaft, as the features of the tine shaft 15 described herein can beemployed equally as well with two separate tine shafts.

As seen in FIGS. 3C and 4, a first distal end 15 a of the tine shaft 15preferably includes a passageway 17 that extends at least partially, ifnot completely, therethrough. The passageway 17 is preferably sized andshaped to receive at least a portion of a fastener 26 (see FIGS. 8 and8A), such as a pin or clip, therethrough. Although the fastener 26 shownherein is a conventional cotter pin, the present invention is not solimited. It is preferred that at least a portion of the first end 15 aof the tine shaft 15 has a reduced diameter or cross-sectional area or aflattened surface 15 a, as compared to at least a remaining portion ofthe preferably generally cylindrical tine shaft 15. In the presentembodiment, the outermost flattened surface of the first end 15 a actsas a locking key. Further, the tine shaft 15 preferably includes anopposing second distal end 15 b (FIGS. 9, 9A, 10, 10A, 11 and 11A) thatis generally identical to the first end 15 a.

Referring FIGS. 1-3C, an assembly or tine assemblies 12 a, 12 b arepreferably selectively removably attached to each end 15 a, 15 b of thetine shaft 15. Each tine assembly 12 a, 12 b includes at least one andpreferably two spaced-apart tine plates or disks 18 (see FIG. 3), or twopair of spaced-apart tine plates 18 (see FIGS. 1-2 and 3A-3C). Each tineplate 18 preferably includes one or more tines, blades or sharpenedprojections 18 a that are sized and shaped to cut through, cultivate ortill soil, for example. Each tine plate 18 preferably includes ten tines18 a projecting radially outwardly from a geometric center of the tineplate 18, but a greater or lesser number of tines 18 a can be used. Thetines 18 a at an outer edge of the tine plate 18 can be rounded toreduce the power requirements needed to turn the blades and not be asaggressive as the pointed blade design. U.S. Pat. No. 5,299,647, whichis assigned to Schiller-Pfeiffer, Inc. and herein incorporated byreference, describes a preferred embodiment of the tine plate.

Referring again to FIG. 1, the tiller 10 preferably includes the frameor a pair of tubes 21 that extend upwardly from the power unit 14 andthe transmission 13 to form two spaced apart handles 22. A cross member23 preferably extends between the two tubes 21. Opposing ends of thecross member 23 are preferably fixedly attached to each of the tubes 21.A cable 24 preferably extends from the power unit 14 to at least one ofthe handles 22 to allow the user to control operation of the power unit14 and, thus, rotation of the tine plates 18 or a brush 36 (see FIG.17), as described in detail below. A lever (not shown) is preferablyoperatively connected to the cable 24 and allows the operator toincrease or decrease the speed of the power unit 14, for example. Thetiller 10 preferably includes an interlock device (not shown) thatprevents the operator from accidentally operating the tiller.

In operation, the operator or user preferably must turn the tiller 10“on” by placing a switch (not shown) in an “on” or start position. Theuser may then be required to start the power unit 14, such as by pullinga cord attached to a reel (not shown) to begin operation of the powerunit 14. Alternatively, the power unit 14 may be started by turning akey (not shown) or simply depressing or pulling a button (not shown).Once the power unit 14 is operating, it is preferred that the user isrequired to press the interlock device in order for the tine plates 18to begin rotating. This feature prevents the user from grabbing thelever and inadvertently operating the tiller without having full controlover the tiller 10. As seen in FIGS. 18-18B and described in detailbelow, the tiller 10 may also be equipped with a reverse mechanization110. The reverse mechanism 110 preferably permits a user to “back-up” orreverse the rotation of the tines 18 a or brush 36 to remove debris,till or cultivate in the opposite direction.

Preferably, the number of tine plates 18 that form the tine assemblies12 a, 12 b can be selectively increased or decreased to create a“larger” or “smaller” tiller 10. For example, one or more tine plates 18can be added to the tine shaft 15 for tilling larger areas or removedfrom the tine shaft 15 to create a more compact tiller 10 for smallertilling tasks. More specifically, each tine assembly 12 a, 12 bpreferably is able to be selectively separated or reduced in size, sothat a single pair of tine plates 18 can be placed on each end 15 a, 15b of the tine shaft 15 so that the tiller 10 can be decreased in lateralsize to maneuver into smaller spaces, for example. Conversely, two pairsof tine plates 18 can be combined or attached to create both the rightand left tine assemblies 12 a, 12 b as shown in FIG. 1A. The assembledright and left tine assembles 12 a, 12 b can then each be attached to anopposing end 15 a, 15 b of the tine shaft 15 so that the tiller 10 canbe increased in lateral size to cultivate larger areas, for example. Theability to provide one set of tine plates 18 on each end 15 a, 15 b ofthe tine shaft 15 or to provide two or more pairs of tine plates 18 oneach end 15 a, 15 b of the tine shaft 15 creates a versatile orconvertible tiller 10.

For example, in preferred embodiments shown in FIGS. 1-2 and 3A-3C, eachtine assembly 12 a, 12 b includes four spaced-apart tine plates 18,wherein an inner pair 18 b (FIG. 3C) of tine plates 18 are connected bya inner hub 39 a (FIG. 3B) and an outer pair 18 c (FIG. 3C) of tineplates 18 are connected by an outer hub 39 b (FIG. 3B). The outer pair18 c of tine plates 18 can be considered the “tine extensions,” whilethe inner pair 18 b of tine plates 18 can be considered the “basetines.” Either the inner pair 18 b or the outer pair 18 c of the tineplates 18 may be mounted to the tine shaft 15 or both pairs 18 b, 18 cmay be connected or combined for mounting to the tine shaft 15. Thisfeature allows the user or operator to selectively reduce or increasethe lateral size of the tiller 10, which currently is not found in theprior art.

Referring specifically to FIG. 3C, the “larger” tiller 10 (FIGS. 1A, 2,3A and 3B) is created, at least in part, by mounting both the inner andouter pair 18 b, 18 c of tine plates 18 to the tine shaft 15.Specifically, at least one and preferably three elongated connectingrods 40 are inserted through spaced-apart apertures (not shown in FIG.3C) in the inner hub 39 a of the inner pair 18 b of tine plates 18. Alongitudinal axis of each aperture preferably extends generally, if notexactly, perpendicular to a plane defined by the hub 39 a. At least aportion of each rod 40 is then inserted into a passageway of at least aportion of an elongated sheath or tube 41. The sheaths 41 preferablyfunction as a spacer or separator to maintain a predetermined or properdistance between the inner and outer pairs 18 b, 18 c of tines plates18. Preferably, each connecting rod 40 extends completely through one ofthe sheaths 41, such that a portion of each connecting rod 40 is exposedon either end of the sheath 41. Next, at least a portion of eachconnecting rod 40 is inserted into one of three spaced-apart apertures(not shown in FIG. 3C) in the outer hub 39 b of the outer pair 18 b ofthe tine plates 18. A nut 42 is then preferably fastened to an outerexposed end of each connecting rod 40 to form the assembled left tineassembly 12 b, for example. Next, the assembled tine assembly 12 b isslid onto the tine shaft 15 and at least one of the fasteners 26 (seeFIG. 3) is inserted into the passageway 17 located between the pair 18b, 18 c of tine plates 18 to secure the tine assembly 12 b to the tineshaft 15. It is preferred that a central axis opening (not shown), whichis generally surrounded by the three spaced-apart apertures, of theinner hub 39 a of the inner pair 18 b of tine plates 18 is sized andshaped to receive at least a portion of the reduced diameter orflattened surface of the tine shaft 15. Alternatively, the pair 18 b, 18c of tine plates 18 may be attached or combined after the inner pair 18b of tine plates 18 has been attached to the tine shaft 15.

Referring to FIGS. 3 and 3C, the “smaller” tiller 10 (FIG. 3) iscreated, at least in part, by mounting only one of the inner and outerpairs 18 b, 18 c of tine plates 18 to the tine shaft 15. If the tineassemblies 12 a, 12 b are originally in the “larger” configuration(FIGS. 1A, 2, 3A and 3B), the inner and outer pair 18 b, 18 c of tineplates 18 must first be separated or disengaged. For example, withrespect to the left tine assembly 12 b, the user may first remove thefastener(s) 26 from the passageway 17 of the tine shaft 15 to allowremoval of the entire left tine assembly 12 b from the tine shaft 15.Next, the user may remove each of the nuts 42 from the ends of theconnecting rods 40, such that the inner and outer pair 18 b, 18 c oftine plates 18 may be separate. Then, either the inner or outer pair 18b, 18 c of tine plates 18 can be mounted directly to the tine shaft 15.For example, the first end 15 a of the tine shaft 15 may be insertedinto and through a central axis opening (not shown) of the outer hub 39b of the outer pair 18 b of tine plates 18. One of the fasteners 26 isthen preferably inserted into the passageway 17 of the tine shaft 15 toattach the outer pair 18 b of tine plates 18 to the tiller 10. Thus, aninnovative feature of the tiller 10 of the present invention is theability to perform the work of a mid-size tiller (i.e., “larger” tiller10 shown in FIGS. 1A, 2, 3A and 3B), weighing only approximately 38 lbs,and convert to a mini tiller (i.e., “smaller” tiller shown FIG. 3) witha weight preferably under approximately 28 lbs.

Referring to FIGS. 1 and 1A, a debris shield or tine shield 19 accordingto a first preferred embodiment of the present invention preferablysurrounds at least a portion of the transmission 13 and is fixedlyattached and/or removably attachable thereto. The tine shield 19 ispreferably sized and shaped to generally cover or surround a top portionof each tine plate 18 when the tine plates 18 are properly attached tothe tine shaft 15. In other words, the tine shield 19 preferablyseparates the motor 14 and operator from the tine assemblies 12 a, 12 b.The tine shield 19 preferably has a generally arcuate shape when viewedfrom either side (see FIG. 1A). An opening 20 is preferably centrallylocated in the tine shield 19 to receive and accommodate an upperportion of the transmission 13 therethrough. In the present embodiment,the tine shield 19 is formed of a single, integral or unitary piece ofmaterial, such as a metallic or polymeric material. Preferably, the tineshield 19 prevents objects, such as soil or debris, from being projectedupwardly or away from the ground surface and toward the operator of thetiller 10. The tine shield 19 may be formed in a variety of sizes andshapes. For example, the tiller 10 may be provided with two separatetine shields each having a distinct surface area (i.e., large andsmall). The large tine shield could be removed and replaced with thesmall tine shield for converting the larger tiller 10 to the smallertiller 10.

Referring to FIGS. 2-3C and 5-6A, a tine shield 43, 43′ according tosecond and third preferred embodiments of the present inventionpreferably includes a central portion 44, 44′, a first or left wing orextension 45 a, 45 a′ and an opposing second or right or wing orextension 45 b, 45 b′. The tine shield 43, 43′ of the second and thirdpreferred embodiments is preferably sized and shaped to generally coveror surround a top portion of each tine assembly 12 a, 12 b when properlyattached to the tine shaft 15, regardless of whether the tine assemblies12 a, 12 b are in “large” (FIGS. 2 and 3A) or “small” (FIG. 3) form.Each of the central portion 44, 45′, the left wing 45 a, 45′ and theright wing 45 b, 45′ preferably has a generally arcuate shape whenviewed from either side. Similar to the first preferred embodiment ofthe tine shield 19, the central portion 44, 44′ of the second and thirdpreferred embodiments of the tine shield 43, 43′ preferably includes anopening 46′ (only labeled in FIG. 5) that is preferably centrallylocated therein to receive and accommodate the upper portion of thetransmission 13 therethrough.

In contrast to the first preferred embodiment, the tine shield 43, 43′of the second and third preferred embodiment is capable of beingselectively expanded or contracted to generally match the width of theleft and right tine assemblies 12 a, 12 b, while preventing objects,such as soil or debris, from being projected upwardly or away from theground surface and toward the operator of the tiller 10. Each of theleft wing 45 a′, the central portion 44′ and the right wing 45 b′ of thethird preferred embodiment includes a flange 47 a, 47 b, 47 c,respectively, that extends from both a front and rear edge thereof. Theflange 47 a, 47 b, 47 c preferably forms an acute or approximatelyninety degree angle with an upper or exterior portion of each of theleft wing 45 a, the central portion 44 and the right wing 45 b.

Further, it is preferred that a bolt or dowel 48, 48′ (FIGS. 2 and 3),for example, is fixedly secured at opposing ends or corners of each wing45 a, 45 b of the second preferred embodiment and each flange 47 b ofthe central portion 44′ of the third preferred embodiment. Each bolt 48,48′ is preferably sized and shaped to fit within a slot or groove 49,49′ of each wing 45 a, 45 b of the second preferred embodiment or one ofthe flanges 47 a, 47 c of the left and right wings 45 a′, 45 b′ of thethird preferred embodiment. The grooves 49, 49′ preferably extendgenerally the entire length of the left and right wings 45 a, 45 a′, 45b, 45′. As shown in FIG. 3C, a nut 50 a and washer 50 b may beassociated with each bolt 48′ of the third preferred embodiment. Thus,while the central portion 44, 44′ is preferably fixedly attached to thetransmission 13, either or each of the left and right wings 45 a, 45 a′,45 b, 45 b′ are movable or slidable with respect to the central portion44, 45′ through the bolt 48, 48′ and slot 49, 49′ combinations. Movementor repositioning of the wings 45 a, 45 a′, 45 b, 45 b′ permits the userto more clearly see and maneuver around or between objects duringtilling, for example, and eliminates the need for the user to remove thetine shield 43, 43′ and store the tine shield 43, 43′ to reduce the sizeof the tiller 10 when not in use. Further, the design of the tiller 10permits folding or sliding into a compact size, enabling the tiller 10to be transported in the trunk of a car (not shown).

The tine shield 43, 43′ may also include a feature to prevent a userfrom operating the tiller 10 if the tine shield 43, 43′ is not sized toproperly cover all or substantially all of the tine assemblies 12 a, 12b. Specifically, an interlocking device or sensor (not shown) may beincluded on or within the tine shield 43, 43′ so that the detection ofthe proper number or sized tine plates 18 is sensed and confirmed.Failure to detect the proper number or sized tine plates 18 preferablystops the operation of the tiller 10. It is preferably possible to lockthe power unit 14 if the detector does not receiving the proper signal.One method for doing this is to imbed a magnet (not shown) into one ormore tines 18 a. If the large tine assemblies 12 a, 12 b are attached tothe tine shaft 15 and the tine shield 43 is not in the extendedposition, the sensor would detect that the tine shield 43 is missing orimproperly configured, and operation of the tiller 10 would not bepossible. Alternatively, a hall effect sensor (not shown), a sonardevice, or a light beam, which must be interrupted or broken to allowoperation of the tiller 10, could be used for the detection of the tineplates 18. Alternatively, a mark may be encoded or embedded into one ofthe tines 18 a. If the proper tine assemblies 12 a, 12 b and tine shield43, 43′ pair were not put in place, the alignment would not complete thecircuit and the power unit 14 would not be able to run.

Referring to FIG. 7, a fourth preferred embodiment of the tine shield 51preferably includes left and right wings or extensions 52 a, 52 b thatare pivotally or rotatably attached to opposing ends of a central shieldportion 53. Specifically, a barrel or living hinge 53 a, for example,may attach an inner edge of each of the left and right wings 52 a, 52 bto an outer edge of the central portion 53. When a particular tillingtask requires the “larger” tiller 10, the operator can simply pivot orrotate the wings 52 a, 52 b downwardly to cover the larger or extendedtine assemblies 12 a, 12 b (FIG. 2). However, when a smaller tillingtask is presented, the operator can pivot or rotate the wings 52 a, 52 bupwardly or away from the ground surface so as only to cover the smalleror reduced tine assemblies 12 a, 12 b (FIG. 3). A latch or lockingmechanism (not shown) may be used to hold the wings 52 a, 52 b in eitheror both positions. Alternatively, the tine shield 51 may be configuredto be rolled-up, rolled-out, folded, unfolded, or turned, for example,to allow the user to selectively expand or reduce the size or shape ofthe tine shield 51.

Referring to FIGS. 8, 8A and 16, a preferred embodiment of a tool 25 isshown for inserting or removing one or more of the fasteners 26 into orout of the passageway 17 of the tine shaft 15. The tool 25 preferablyincludes a first end 27 a that is sized and shaped to receive or hold atleast a portion of one of the fasteners 26. An opposing second end 27 bof the tool 25 may include a hook or catch (see FIG. 16) for engaging orsurrounding a portion of the fastener 26 to allow the user to moreeasily remove the fastener 26 from the passageway 17 of the tine shaft15. The tool 25 is preferably of a sufficient length, as measured fromthe first end 27 a to the second end 27 b, to allow a user to insert thefastener 26 into the passageway 17 of the tine shaft 15 withoutrequiring the user's hand(s) to enter the space between adjacent tineplates 18.

The tool 25 allows a user or operator to more easily insert or removethe fastener 26 from the passageways 17 of the tine shaft 15 withoutunnecessarily disassembling certain portions of the tiller 10 or riskinginjury by inserting a hand or finger proximate the sharp blade 18 a of atine plate 18. In conventional tillers, a tool is not necessary toinsert a fastener into an end of a tine shaft because the end is exposedand relatively easily accessible to the user. However, the first andsecond ends 15 a, 15 b of the tine shaft 15 of the present invention maynot be as easily accessible because the ends 15 a, 15 b can be locatedbetween the pair 18 b, 18 c of tine plates 18.

FIGS. 9-9C show a second preferred embodiment of the “large” right tineassembly 12 a, with a second preferred embodiment of the “large” lefttine assembly 12 b being a mirror image thereof. In the presentlypreferred embodiment, the inner pair 18 b of tine plates 18 is attachedto the outer pair 18 c of tine plates 18 by a connector piece 73. Theconnector piece 73 preferably includes three connecting rods 74 fixedlyor removably held in a spaced-apart relation by a plate 75 thatpreferably defines a plane that extends perpendicularly to alongitudinal axis of each connecting rod 74. At least one end of eachconnecting rod 74 preferably includes a threaded portion 74 a (FIGS. 9Band 9C). A supporting shaft 76, which is preferably identical or similarto either end 15 a, 15 b of the tine shaft 15, preferably extends fromat least one side of the plate 75.

In operation, the tine plates 18 may be attached to the tine shaft(s) 15in a variety of manners. For example, the connecting rods 74 of theconnector piece 73 may be inserted into a respective aperture 77 a ofthe inner pair 18 b of tine plates 18. The nut(s) 78 a and washer(s) 78b may then be attached to at least a portion of each connecting rod 74so as to attach the connector piece 73 to the inner pair 18 b of thetine plates 18. The combined connector piece 73 and inner pair 18 b oftine plates 18 may then be attached to the tine shaft 15. Alternatively,the inner pair 18 b of tine plates 18 may first be attached directly tothe tine shaft 15, as if to create the “smaller” tiller, or the innerpair 18 b can be first attached directly to the outer pair 18 c of tineplates 18. Next, an end of each connecting rod 74 is preferably insertedinto spaced-apart apertures 77 a (FIG. 9) in the inner hub 39 a of theinner pair 18 b of tine plates 18. A nut 78 a and a washer 78 b arepreferably threaded onto one end 74 a of each connecting rod 74 toattach the connector piece 73 to the inner pair 18 b of tine plates 18.The opposing end of each connecting rod 74 is then inserted intospaced-apart apertures 77 b (FIG. 9) in the outer hub 39 b of the outerpair 18 c of the tine plates 18. In addition, the support shaft 76 isinserted through a central opening 77 c (FIG. 9) of the outer hub 39 bof the outer pair 18 c of the tine plates 18. Finally, a fastener 26 ispreferably inserted into a passageway 79 of the support shaft 76. Asmentioned above, it is understood that the inner and outer pair 18 b, 18c of tine plates 18 may first be attached together, and then thecombined pairs 18 b, 18 c may be attached to the tine shaft 15. FIG. 9Dshows a modified version of the above-described embodiment of theconnector piece 73 shown in FIGS. 9-9C. In the modified version shown inFIG. 9D, the connector piece 73 includes two spaced-apart plates 75 butis used in generally the same manner.

FIGS. 10 and 10A show a third preferred embodiment of the “large” righttine assembly 12 a, with a third preferred embodiment of the “large”left tine assembly 12 b being a mirror image thereof. The thirdpreferred embodiment is substantially similar to the embodimentsdescribed above. Specific similarities between the second and thirdpreferred embodiments are omitted herein for the sake of brevity andconvenience, and therefore is not limiting. A distinguishing feature ofthe third preferred embodiment is that the connector piece 73 includesthree connecting rods 80, wherein each connecting rod 80 includes athreaded first end 80 a, a middle portion 80 b of increased size ordiameter, and an opposing second end 80 c having a passageway (notshown) therethrough. The passageway in the second end 80 c is preferablysized and shaped to receive at least a portion of a fastener 26 therein.

In operation of one preferred method, after the inner pair 18 b of tineplates 18 is attached directly to the tine shaft 15, as described indetail above, the first end 80 a of each connecting rod 80 is thenpreferably inserted into the spaced-apart apertures 77 a in the innerhub 39 a of the inner pair 18 b of the tine plates 18 and the washers 78b and nuts 78 a are installed on the first end 80 a of each connectingrod 80. Next, the second end 80 c of each connecting rod 80 ispreferably inserted into one of the spaced-apart apertures 77 b in theouter hub 39 b of the outer pair 18 c of the tine plates 18. It is thenpreferred that one fastener 26 is inserted into the passageway of thesecond end 80 c of each connecting rod 80. Alternatively, it isunderstood that the inner and outer pair 18 b, 18 c of tine plates 18may be attached together before the combined pairs 18 b, 18 c areattached to the tine shaft 15.

FIGS. 11-11C show a fourth preferred embodiment of the “large” righttine assembly 12 a, with a fourth preferred embodiment of the “large”left tine assembly 12 b being a mirror image thereof. The fourthpreferred embodiment is substantially similar to the second preferredembodiment described above. Specific similarities between the second andfourth preferred embodiments are omitted herein for the sake of brevityand convenience, and therefore is not limiting. A distinguishing featureof the fourth preferred embodiment is that the connector piece 73includes six connecting rods 81, wherein three of the connecting rods 81extend from a first side of a plate 82 and the three remainingconnecting rods 81 extend from an opposing second side of the plate 82.As seen in FIGS. 11 and 11B, it is preferred that no two connecting rods81 that extend from opposing sides of the plate 82 define a commonlongitudinal axis. In other words, it is preferred that each connectingrod 81 is staggered around the circumference or perimeter of the plate82.

Further, it is preferred that each connecting rod 81 includes at leastone radially outwardly extending projection or detent 83 proximate anend thereof distal from the plate 82. The at least one projection 83preferably includes a generally angled surface. Each projection 83 ispreferably sized and shaped to maintain or hold each tine pair 18 b, 18c onto the connector piece 73 and generally eliminate the need for afastener 26. A snap-ring or washer 78 b (see FIGS. 11 and 11A) may beremovably attached to each connecting rod 81. In light of thedescription provided above for assembling the second and third preferredembodiments of the “larger” right tine assembly 12 a, one of ordinaryskill in the art would understand how to assemble the “larger” righttine assembly 12 a of the fourth preferred embodiment. As a result,description thereof will be omitted for the sake of brevity.

FIGS. 12 and 12A show a fifth preferred embodiment of the “large” righttine assembly 12 a, with a fifth preferred embodiment of the “large”left tine assembly 12 b being a mirror image thereof. The fifthpreferred embodiment is substantially similar to the third preferredembodiment described above. Specific similarities between the third andfifth preferred embodiments are omitted herein for the sake of brevityand convenience, and is not limiting. A distinguishing feature of thefifth preferred embodiment is that the connector piece 73 includes afastener 26 on each end of the three spaced-apart connecting rods 80.The fasteners 26 properly maintain the connector piece 73 between thetwo pair 18 b, 18 c of tine plates 18, and eliminate the need for thethreaded first end 80 a and various nuts 78 a and washer 78 b of thethird preferred embodiment (FIGS. 10 and 10A).

FIGS. 13 and 13A show a sixth preferred embodiment of the “large” righttine assembly 12 a, with a sixth preferred embodiment of the “large”left tine assembly 12 b being a mirror image thereof. The sixthpreferred embodiment is substantially similar to the third preferredembodiment described above. Specific similarities between the third andsixth preferred embodiments are omitted herein for the sake of brevityand convenience, and is not limiting. A distinguishing feature of thesixth preferred embodiment is that the connector piece 73 includes alocking cap 84 for removably attaching to the second end 80 c of each ofthe three spaced-apart connecting rods 80. As shown in FIG. 13A, thelocking cap 84 preferably includes a handle or gripping portion 84 agenerally surrounded by three spaced-apart openings 84 b that are eachsized and shaped to receive and retain at least a portion of the secondend 80 c of one of the connecting rods 80. Each opening 84 b preferablyincludes a larger, generally circular portion adjacent to a smaller,generally circular portion to create a selectively lockable cap 84.

The locking cap 84 preferably properly maintains the connector piece 73between the two pair 18 b, 18 c of tine plates 18, and eliminates theneed for the fasteners 26. Specifically, after the inner and outer pair18 b, 18 c of tine plates 18 are attached together and then slid ontothe tine shaft 15, one fastener 26 is preferably inserted into thepassageway 17 of the tine shaft 15 and the locking cap 84 is slid overat least a portion of the second end 80 c of each connecting rod 80. Thelocking cap 84 is then preferably rotated with respect to the connectingrods 80 such that the smaller portion of each opening 84 b fits within agroove 85 at or in the second end 80 c of each connecting rod 80. Thecombination of the smaller portion of each opening 84 b and the groove85 in each connecting rod 80 creates a secure connection between theconnector piece 73 and the right tine assembly 12 a.

FIG. 14 shows a seventh preferred embodiment of the “large” right tineassembly 12 a, with a seventh preferred embodiment of the “large” lefttine assembly 12 b being a mirror image thereof. The seventh preferredembodiment is substantially similar to the sixth preferred embodimentdescribed above. Specific similarities between the sixth and seventhpreferred embodiments are omitted herein for the sake of brevity andconvenience, and is not limiting. A distinguishing feature of theseventh preferred embodiment is that the connector piece 73 includes awing nut 86 or similar finger-tightening device for fixing the righttine assembly 12 a, for example, to the tine shaft 15. The wing nut 86is preferably directly attachable to a distal end of a support shaft(not shown) similar to the support shaft 76 of the second preferredembodiment (FIGS. 9-9C) describe above. The wing nut 86 eliminates theneed for the locking cap 84 of the sixth preferred embodiment.

Referring to FIGS. 15 and 15A, the tiller 10 preferably includes aclutch or clutch drum assembly 31 that interfaces between the power unit14 and the transmission 13. In other words, the clutch drum assembly 31is installed between the motor 14 and the transmission 13 and is thelink between the motor 14 and the transmission 13, so that the tines 18a can stop spinning or rotating without the operator having to turn offthe motor 14. The clutch 31 of the present invention is capable ofwithstanding the excessive vibrations the tine extensions 18 a maycreate. As seen in FIG. 15A, the clutch 31 preferably includes a clutchdrum 32, a bearing 33, a snap or o-ring 34 and a clutch adapter 35. Theclutch 31 is preferably fixedly attached to the power unit 14 by one ormore bolts (not shown) and is attached to the housing 16 of thetransmission 13 by tightening a bolt (not shown) that preferably extendsin a direction generally perpendicular to the one or more bolts thatattach the clutch drum 32 to the power unit 14.

When properly assembled, the generally circular or cylindrical bearing33 is located within a generally circular recessed area 87 of the clutchdrum 32. The bearing 33 preferably includes a generally circular centralopening 33 a that extends completely through the bearing 33 from a topsurface 88 a to a bottom surface 88 b thereof It is preferred that thegenerally circular snap ring 34 is placed directly on the top surface 88a of the bearing 33, opposite the recessed area 87. A generallycircular, centrally-located extension 89 of the clutch adapter 35 ispreferably inserted within an opening of the snap ring 34, the opening33 a of the bearing 33 and into an interior of the clutch drum 32.

This clutch 31 preferably works automatically through the use ofcentrifugal force. A pair of clutch shoes (not shown) is preferablyattached to the motor 14, along with a spring (not shown) that keeps theclutch shoes in a retracted configuration. If the clutch shoes arespinning slowly enough, the clutch shoes are held against the motorshaft by the spring. If the motor 14 spins fast enough (because theoperator has pulled the throttle trigger to begin tilling), thecentrifugal force on the clutch shoes overcomes the force being appliedby the spring, and the clutch shoes are slung outwardly. The clutchshoes preferably come in contact with an inside of the clutch adapter 35and the clutch adapter 35 starts spinning. The clutch adapter 35, theclutch shoes and the shaft of the motor 14 become a single spinning unitdue to the friction between the clutch shoes and the clutch adapter 35,thus transmitting rotation through the transmission 13 and driveshaft(s) 15 to the tines 18 a. At this point, the tines 18 a begin tomove or rotate. The clutch 31 preferably disengages when the motor 14 isidling.

FIG. 16 shows a second preferred embodiment of the cross member 23′,wherein like numerals are utilized to identify like elements and a primesymbol (′) is utilized to distinguish like components of the crossmember 23′ of the second preferred embodiment from the cross member 23of the preferred embodiment described above. In the second preferredembodiment, only a portion of first and second ends 23 a′, 23 b′ aregenerally arcuate or concave in shape. More specifically, a centralportion of each end 23 a′, 23 b′, as measured along the height H′ of thecross member 23′, is generally arcuate or concave, while the remainingportions of each end 23 a′, 23 b′ are planar or coplanar with the bodyof the cross member 23′. It is preferred that a hole 90′ extends throughthe central portion of each end 23 a′, 23 b′.

The body or middle of the cross member 23′ preferably includes at leastone and possibly two vertically-spaced apart catches 91. The catches 91preferably extend from or are located on a rear surface 92 of the crossmember 23′. Each catch 91 is preferably sized and shaped to receive andretain at least a portion of the tool 25. Thus, the tool 25 may beremovably attached to the cross member 23′.

Referring to FIGS. 17-17B, the tiller 10 may be selectively converted ormodified to replace the tine plates 18 with the brush 36, for example,for dispersing dirt or snow. The brush 36 is preferably sized and shapedto work in conjunction with various portions of the tiller 10.Specifically, a tube or cover 94 is preferably placed or slid over thetine shaft(s) 15 (not shown in FIGS. 17-17B). One or more fasteners 26are preferably inserted through a hole of each tube 94 and into thepassageway 17 at each end 15 a, 15 b of the tine shaft 15, such thattubes 94 are rotatably fixed to the tine shaft(s) 15 and rotation of thetine shaft 15 causes rotation of the tubes 94. A first or inner end 94 aof each tube 94 preferably includes a freely-rotatable wheel 95 thatsupports the transmission 13, and the remaining portions of the tiller10, above the ground surface. The two spaced-apart wheels 95 arepreferably sized and shaped to movably support the tiller 10 on theground surface. An opposing second or outer end 94 b of one of the tubes94, which is preferably rotatable with respect to a first outer endplate 38 a, preferably includes a first gear 37 a fixedly attachedthereto. The second end 94 b of the other tube 94 is rotatably attachedto an extension 96 of a second outer end plate 38 b, such that the tube94 is rotatable with respect to, but supported by, the second outer endplate 38 b.

As shown in FIGS. 17A and 17B, it is preferred that one or moredrivingly connected gears 37 b, 37 c, 37 d, which are rotatably attachedto extensions 96 b, 96 c, 96 d, respectively, fixedly attached to aninterior surface of the first outer end plate 38 a, rotatably engage thefirst gear 37 a. Thus, rotation of the first gear 37 a rotates the oneor more additional gears 37 b, 37 c, 37 d. The last gear 37 d (i.e., theadditional gear 37 d) is preferably fixedly attached to a least aportion of the brush 36, such that rotation of the last gear 37 drotates the brush 36. Thus, the combination of gears 37 a, 37 b, 37 c,37 d preferably transfers rotational movement or motion from the tineshaft 15 to the brush 36. The present invention is not limited to theabove-described and shown number, size, type or orientation of gears 37a, 37 b, 37 c, 37 d, as the above-identified characteristics could bemodified to accomplish the desired functions. In other words, the brush94 is operatively connected to at least one and preferably both tubes 94such that rotation of the tube(s) 94 rotates the brush 36 for dispersingat least one of snow, dirt and dust.

FIGS. 18-18B show a preferred embodiment of the reverse mechanism 110.FIG. 18 shows the reverse mechanism 110 in a first or disengagedposition, wherein the tine shaft 15 is driven or rotated in a forwarddirection (i.e., counterclockwise). FIG. 18A shows the reverse mechanism110 in a second or neutral position, wherein the tine shaft 15 is notoperatively engaged with or driven by the power unit 14. FIG. 18B showsthe reverse mechanism 110 in a third or engaged position, wherein thetine shaft 15 is driven or rotated in a reverse direction (i.e.,clockwise). The reverse mechanism 110 preferably includes a drive shaft111 that is operatively connected to the power unit 14, such that thepower unit 14 drives or rotates the drive shaft 111 through thetransmission 13 in preferably one rotational direction (i.e.,clockwise). The drive shaft 111 is preferably at least partiallysurrounded by the housing 16.

The drive shaft 111 is preferably a double-direction worm, meaning thatthe worm drive shaft 111 includes a first set of threads 111 a on anexterior surface thereof that are generally angled with respect to andspaced-apart from a second set of threads 111 b on an exterior surfacethereof. In the present embodiment, the first set of threads 111 a isconsidered the “forward” set and the second set of threads 111 b isconsidered the “reverse” set. In the present embodiment, the first setof threads 111 a are angled at approximately a ninety degree angle withrespect to the second set of threads 111 b. The shape and/orconfiguration of the threads 111 a, 111 b is not limited to thegenerally curved orientation shown in FIG. 18-18B, but instead may begenerally straight or linear, for example.

Further, the reverse mechanism 110 preferably includes a first orforward gear 112, a second or tine gear 113 and a third or reverse gear114. Each gear 112, 113, 114 is preferably supported at least partially,if not entirely, within the housing 16. The forward and reverse gears112, 114 each preferably include a series of teeth on an outer peripherythereof that are sized and shaped to continuously and constantly engagea series of teeth on an outer periphery of the tine gear 113. The tinegear 113 is preferably directly supported by and rotatably mounted to aninternal portion of the housing 16 of the transmission 13. The tine gear113 is preferably fixedly attached to the tine shaft 15, such thatrotation of the tine gear 113 rotates the tine shaft 15. The forward andreverse gears 112, 114 are preferably directly supported by androtatably mounted to a member or plate 115 (portions of which are shownin solid and phantom lines in FIGS. 18-18B). The plate 115 is preferablydirectly supported by and/or within, and movably mounted, such asrotatably or pivotally, to an internal portion of the housing 16 of thetransmission 13. Thus, movement or rotation of the plate 115 preferablymoves the forward and reverse gears 112, 114 toward and in contact with,or away and out of contact with, the worm drive shaft 111.

The cable 24 is preferably operatively or directly attached to theforward gear 112. Alternatively, the cable 24 may be directly attachedto the plate 115, for example. A grommet seal 117, which may be locatedwhere the cable 24 enters the housing 16 of the transmission 13,preferably prevents dirt and debris, for example, from entering theinterior of the housing 16. The lever operatively connected to the cable24, as described above, preferably allows a user to selectively engageor disengage the reverse mechanism 110. At least a portion of thereverse gear 114 is preferably directly attached to an internal portionof the housing 16 of the transmission 13 by a biasing member or spring116, such as a tension coil spring. Alternatively, the spring 116 maydirectly attach a portion of the plate 115 to an internal portion of thehousing 16. The spring 116 preferably biases the reverse mechanism 110in the disengaged position when the lever or reverse mechanism 110 isnot selectively engaged by the user, such that the reverse gear 114 isnot in contact with the worm drive shaft 111 and the tine shaft 15 isnot rotated in the reverse direction.

In operation, the reverse mechanism 110 is preferably normally biased tothe disengaged position or forward configuration shown in FIG. 18. Morespecifically, unless the lever is selectively moved or manipulated bythe user in a predetermined fashion or into a predetermined position,the forward gear 112 engages both the worm drive shaft 111 and the tinegear 113 to rotate the tine shaft(s) 15 in a forward direction when thepower unit 14 is energized or “on.” In this configuration, the reversegear 114 is not driven and simply acts as an idle gear. However, whenthe user or operator desires to reverse the rotation of the tine plates18, the operator preferably selectively manipulates or moves the leverin a predetermined fashion, which causes the cable 24 to disengage(i.e., pull) the forward gear 112 away from and out of engagement withthe worm drive shaft 111. Once the forward gear 112 is disengaged fromthe worm drive gear 111, the reverse mechanism 110 is preferably in theneutral position or configuration as shown in FIG. 18A at leastmomentarily, because neither the forward or reverse gears 112, 114 areengaged with or driven by the worm drive shaft 111. Thus, in the neutralposition of the reverse mechanism 110, neither the tine gear 113 nor thetine shaft 115 is driven. Conventional mini-tillers do not include aneutral position.

To reverse the rotation of the tines 18, the lever is either held in theabove-described predetermined position or manipulated or moved toanother predetermined position, which causes the cable 24 to continue tomove the forward gear 112 away from the worm drive gear 111 and move thereverse gear 114 into contact or engagement with the worm drive gear111, as shown in FIG. 18B. In the reverse or third configuration shownin FIG. 18B, rotation of the worm drive gear 111 rotates the tine gear113 in the reverse direction, which in turn rotates the tine plates 18in the reverse direction. In this configuration, the forward gear 112 isnot driven and simply acts as an idle gear. The reverse mechanism 110 isnot limited to operation with the tine plates 18, as the reversemechanism 110 may reverse the rotation of the brush 35 or any otherattachment of the tiller 10. The reverse mechanism 110 of the presentinvention eliminates the requirement of conventional tillers for theuser to leave the operating position and manually reposition or relocategears to reverse operation of the tines. In addition, the reversemechanism 110 of the present invention eliminates the need for a slot inthe body of a conventional tiller that allows dirt and debris, forexample, to enter the internal components of the tiller 10 andnegatively affect operation thereof.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

We claim:
 1. A device for cultivating soil or brushing debriscomprising: a frame supporting a transmission and a motor, thetransmission defining a housing; a drive shaft at least partiallysurrounded by the housing and being driven by the motor through thetransmission, the drive shaft being a worm having a first set of threadson an exterior surface thereof and a second set of threads on theexterior surface thereof, the first set of threads being spaced-apartfrom and angled with respect to the second set of threads; a first gear,a second gear, and a third gear all supported at least partially withinthe housing, external teeth of the second gear being in constantengagement with external teeth of both the first and third gears, atleast one of the first and third gears being configured to beselectively disengaged from the drive shaft; a shaft fixedly attached tothe second gear; and an assembly removably attachable to the shaft. 2.The device according to claim 1 wherein selective engagement of theexternal teeth of the first gear with the first set of threads of thedrive shaft rotates the shaft in a first rotational direction, andselective engagement of the external teeth of the third gear with thesecond set of threads of the drive shaft rotates the shaft in anopposite second rotational direction.
 3. The device according to claim 1further comprising: a member rotatably supporting each of the first andthird gears, the member being located within and rotatably supported byat least a portion of the housing.
 4. The device according to claim 3further comprising: a spring attaching at least a portion of one of themember and the third gear directly to a portion of the housing, thespring biasing the third gear away from the drive shaft.
 5. The deviceaccording to claim 3 further comprising: a lever pivotably mounted tothe frame, the lever being selectively actuated by a user; and a cabledirectly attaching at least a portion of one of the member and the firstgear to the lever.
 6. The device according to claim 3 wherein the memberis pivotable between a first configuration in which the first geardirectly engages the first set of threads, a second configuration inwhich neither the first gear nor the third gear directly engages thefirst or second set of threads, and a third configuration in which thethird gear directly engages the second set of threads.
 7. The deviceaccording to claim 1 wherein the first set of threads of the drive shaftextend at an angle of approximately ninety degrees with respect to thesecond set of threads of the drive shaft.
 8. The device according toclaim 1, wherein the assembly is a tine assembly including at least oneblade for directly engaging and cultivating soil.
 9. The deviceaccording to claim 1, wherein at least one tool is attached to theshaft.